Control valve pressure bleed inspection port

Abstract

A valve with an integral means for bleeding internal pressure prior to separation of a bonnet for the valve from its engagement with the valve body, provided by a bore through the valve body. This allows the internal pressure of the valve to equalize with atmospheric pressure prior to complete disassembly of the bonnet from the valve body. The bore through the valve body also serves as a leak detector, by providing a path for fluids passing through the valve to leak to the exterior of the valve body in the event of a failure of the seal between the bonnet and the valve body, which can readily be detected by passersby upon inspection of the exposed end of the bore at the exterior of the valve body.

We claim:  
     
       1. An improvement to a valve having a valve body, a bonnet threadedly securable to the valve body, said valve body having an interior wall, an exterior wall, and an interior cavity defined by the interior wall, the improvement comprising: 
       a bore extending from a first open end at the interior wall of the valve body to a second end at the exterior wall of the valve body, said first open end located at a position of the interior of the valve body such that said bonnet exposes said bore to an interior cavity defined by the interior wall of the valve body prior to removal of the bonnet from a threaded engagement with the valve body, and;  
       a gasket disposed along the interior wall of the valve body, prior to the threaded engagement, to create a pressure-assisted fluid seal between said bonnet and said valve body wherein said gasket is directly exposed to an operating pressure of the valve and a fluid passing therethrough when said bonnet is threadedly engaged with said valve body.  
     
     
       2. The valve of  claim 1 , the improvement further comprising that, upon exposure of the bore to the interior cavity, an internal pressure of the valve is equalized with atmospheric pressure. 
     
     
       3. The valve of  claim 2 , wherein the improvement further provides a means for detection of a leak in an engagement of said bonnet and said valve body, including said bore providing a path for leaked fluid within the valve body to travel from the first end of the bore to the second end of the bore at the exterior wall of the valve body, whereby said leaked fluid is detectable from outside the valve body. 
     
     
       4. The valve of  claim 1 , wherein the valve is a downward flow valve having an inlet passageway and an outlet passageway, the inlet passageway being located higher than the outlet passageway. 
     
     
       5. The valve of  claim 1 , wherein the valve is an upward flow valve having an inlet passageway and an outlet passageway, the inlet passageway being located lower than the outlet passageway. 
     
     
       6. The valve of  claim 1 , wherein the valve has an inlet passageway and an outlet passageway, the inlet passageway and the outlet passageway being located at the same height. 
     
     
       7. A valve assembly comprising: 
       a valve body having an interior wall and an exterior wall;  
       a bonnet threadedly engageable with said valve body;  
       an interior cavity defined by the interior wall, said interior cavity having an inlet passageway, an outlet passageway;  
       a gasket disposed along the interior wall prior to the portion that threadedly receives the bonnet, the gasket providing a pressure-assisted seal at an intersection of said bonnet and the interior wall of the valve body wherein said gasket is directly exposed to an operating pressure of the valve and a fluid passing therethrough when the bonnet is completely threadedly received in the valve body, and;  
       a bore extending through the valve body from the interior cavity to the exterior wall, the bore being sealingly covered by the bonnet when the bonnet is completely threadedly received in the valve body and the bore permitting at least one of the group of equalization of the operating pressure and the passing of fluid therethrough prior to the bonnet being completely removed from threaded engagement with the valve body.  
     
     
       8. The valve of  claim 7 , wherein the valve is a downward flow valve having an inlet passageway and an outlet passageway, the inlet passageway being located higher than the outlet passageway. 
     
     
       9. The valve of  claim 7 , wherein the valve is an upward flow valve having an inlet passageway and an outlet passageway, the inlet passageway being located lower than the outlet passageway. 
     
     
       10. The valve of  claim 7 , wherein the valve has an inlet passageway and an outlet passageway, the inlet passageway and the outlet passageway being located at the same height. 
     
     
       11. The valve assembly of  claim 7 , further comprising a cover associated with an end of the bore at the exterior wall of the valve body, the cover being actuated upon release of internal pressure through the bore from a closed position substantially covering the end of the bore to an open position.